Divisible thermoplastic egg carton

ABSTRACT

The present invention relates to egg cartons which comprise an inverted dish-like cover section integrally joined to a bottom cellular section, the bottom cellular section having integrally joined thereto along its longitudinal edge a locking flap. The bottom cellular section of the cartons are characterized by having at least one rib extending transversely across the bottom section, the rib acting as a separating means for eggs contained in the bottom cellular section. The carton is capable of division into two sections by virtue of a slit which extends longitudinally along the centrally located transverse rib in the cellular section of the bottom.

United States Patent Jackson 1 Sept. 30, 1975 [54] DlVlSIBLETHERMOPLASTIC EGG 3.519.189 7/1970 Bambera et al... 229/45 CARTON3,648916 3/l972 Commissomn 229/44 R X 3.721.360 3 1973 Collie 215/1 c x[75] Inventor: William B. Jackson, Can-andaigua,

Primary ExaminerWilliam I. Price [73] Assignee: Mobil Oil Corporation,New York. P Marcus N Y Attorney, Agent, or Firm-Charles A. Huggett;James D. Tierney [22] Filed: Mar. 14, 1974 1 1 pp No; 450,970 57ABSTRACT Related US. Application Data The present invention relates toegg cartons which [63] Continuation of Scr. No. 236.620, March 21 1972.comprise an inverted dish-like Cover Section integrally abandoned.joined to a bottom cellular section, the bottom cellular section havingintegrally joined thereto along its longi- [52] US. Cl. 229/51 DB;229/2.5; 229/44 R; tudinal edge a locking flap. The bottom cellular sec-229/45 tion of the cartons are characterized by having at least [51]Int. Cl. B65D 1/26; B65D 17/24 one rib extending transversely across thebottom sec- {58] Field of Search 2.29/25, 44 R. 45, 51 DB; tion, the ribacting as a separating means for eggs con- 220/9 F tained in the bottomcellular section. The carton is capable of division into two sections byvirtue of a slit [56] References Cited which extends longitudinallyalong the centrally lo- UNITED STATES PATENTS cated transverse rib inthe cellular section of the bot- 2.130 37s 9/1938 Bueschel 229/51 DB x2152.649 4/1939 Jones. 229/51 DB X 3 Claims, 6 Drawing Figures 3.335.8468/1967 Mllls 220/) F X U.S. Patent Sept. 30,1975 Sheet 1 of 2 3,908,891

US. Patent Sept. 30,1975 Sheet 2 012 3,908,891

DIVISIBLE THERMOPLASTIC EGG CARTON This is a continuation of applicationSer. No. 236,620 filed Mar. 21, 1972, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates to cellular egg carton structures comprising eggcartons having twelve egg receiving cavities which may be manuallysubdivided into two separate carton sections, each individual sectionhaving six egg receiving cavities.

2. Description of the Prior Art In the past, egg carton structurescomprising an inverted dish-like cover section, and a bottom cellularsection with a locking flap attached thereto have commonly been employedto contain eggs for the retail purchaser. The cellular arrangement ofsuch cartons usually comprises twelve egg receiving cells arranged intwo longitudinally extending rows of cell pares, each row consisting ofsix individual egg receiving cells. Oftentimes, however, therequirements of the purchaser, or alternatively the consumer, of such aproduct are less than one-dozen and, for example, his needs orrequirements may be suited by the purchase of six eggs. In order tosatisfy the requirements of such an individual it has been commonplace,in the past, to provide one-dozen capacity egg carton structurescharacterized by having a line of weakness, susceptible to manualfracturing, continuously extending around the central portion of thecarton structure. When such cartonsare formed of fibrous pulp material,the centrally located line of weakness around the cartons center maycomprise a score line which weakens the resistance of the pulp cartonstructure to fracturing along such a line when manual pressure isapplied to the ends of such a carton, whereby the carton splits into twosections, each section containing six eggs.

Although such an arrangement has been employed in the past for providingdivisible pulp cartons, no similar structural arrangement has beencommercially employed, when it is desired to produce a divisible cartonfabricated from plastic materials, such as for example polystyrene, andin particular a polystyrene foam egg carton. Moreover, to the best of myknowledge, divisible plastic egg cartons, including foam cartons, arenot currently commercially available.

In the case of plastic egg cartons, such as polystyrene I foam eggcartons, when a line susceptible to manual fracturing similar to thathereinabove described is SUMMARY OF THE INVENTION For purposes ofclarity in describing the present invention, carton structures of thetype disclosed in U.S. Pat. No. 3,648,916 are employed. It will be notedthat in the bottom cellular portion of such cgg cartons, the cell wallsare employed, in part, to separate individual eggs contained within thecell receptacles from contact with one another. For example, in U.S.Pat. No. 3,648,916 at least one centrally located transverse rib extendsacross the bottom cellular portion of the carton. In accordance with thepresent invention, it has been found that a continuous slit, whichextends completely orsubstantially through the top portion of thecentrally located transverse, egg cell barrier rib, will not materiallyeffect the strength of the carton and,

moreover, will provide a basis for forming a divisible carton, such as adivisible plastic carton.

The present invention provides an egg carton structure comprising abottom cellular section and an inverted dish-like cover section hingedthereto. A slit is provided longitudinally across the top of thecentrally positioned transverse egg separating means in the bottomcellular portion of the carton. When a carton locking flap is employedto secure the cellular bottom and carton cover portions in a releaseablylocked position, a row of perforations, or alternatively a slit, extendsthrough the central portion or at the edge of such a locking flap, inalignment with the centrally located slit in the bottom cellularsection. Additionally, the carton structures of the present inventionare characterized by having a series of perforations or, alternatively,elongated slits extending transversely across the carton cover backwall, top wall, and front wall substantially in alignment with thecentrally located slit in the cellular bottom section.

Materials which may be employed to form the divisible egg cartons of thepresent invention include, for example, cardboard, chipboard, fibrouspulp, plastic; including foamed plastics suchas polystyrene; high impactpolystyrene, polyolefins, polyvinyl chlorides, polyesters such aspolyethylene terephthalate, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a top planar view of anembodiment of the inside of a completely opened egg carton structure ofthe present invention.

FIG. 1b is a perspective view of the carton structure, illustrated inFIG. la, as the carton is being closed.

FIG. 2 is a perspective view of the carton structure illustrated inFIGS. la and 1b after the carton has been closed and subsequentlydivided into two separate carton sections.

FIG. 3 is an end view of one of the carton sections illustrated in FIG.2.

FIG. 4 is a fragmentary top planar view of another embodiment of thecarton structures of the present invention.

FIG. 5 is a fragmentary top planar view of still an additionalembodiment of the carton structures of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS As illustrated in FIGS. 1a and lb ofthe attached drawing, one embodiment of the divisible egg cartonstructures contemplated within the scope of the present invention,comprises a dish-like cover section 10 integrally hinged along hingemember 21 to a bottom cellular section 15, the bottom cellular section15 additionally has hinged thereto along hinge member 17 a locking flap18. The twelve-cell carton structure illustrated in FIGS. 1a and 1b hasa bottom cellular section 15 which comprises two longitudinallyextending rows of egg receiving cavities 16, each row comprising sixreceiving cavities. In the embodiment illustrated in FIGS.

1a and 1b it will be noted that the carton cover section comprises acover back wall 14 integrally joined to cover top wall 12 which in turnis integrally joined to 'carton cover front wall 11. Carton cover 10 hasside walls 13 at opposite ends of the carton cover section connectingfront wall 11 with back wall 14. As more clearly illustrated in FIG. 1bthe carton structure may into contact with transverse rib 40 located inthe bottom cellular section 15 whereby, when compressive forces areexerted against the cover of the carton when it is in a closed position,such forces will be resisted to avoid egg breakage by virtue of supportpost 22 bearing against transverse rib 40.

When it is desired to close and releaseably lock the carton structureshown in FIGS. 1a and 1b, carton locking flap 18 is pivoted around hinge17 to an upright vertical position as'illustrated in FIG. 1b and, whenthe carton is completely closed as shown in FIG. 2, locking flap l8bears against the inside of the carton cover front wall 11. The cartonis maintained in a closed position by virtue of the engagement of theedge detent 20,

adjacent aperture 19, with locking rib 41 located on carton locking flap18 as illustrated in FIG. 112. When it is desired to reopen such acarton, an inwardly exe rted digital pressure may be applied againstlocking rib 41 which causes disengagement thereof with detent 20allowing the carton to assume an open position. As further illustratedin FIGS. la and lb, the specific embodiment shown therein ischaracterized by having a slit B extending longitudinally substantiallyacross the length of transverse rib 40. Another slit C is formed in thebase of the cover support post 22 in substantial longitudinal alignment(when the carton is in its opened position) with slit B. Additionally,perforations A when the carton is in its open position as shown in FIG.la, extend in substantially longitudinal alignment with slits C and'B.It will be noted that perforations A extend transversely along andthrough carton cover front wall 11, carton top wall 12, carton back wall14 and carton locking flap 18.

When the carton as illustrated in FIGS. 1a and lb is loaded with eggsand is in a closed position, perforation A and slits C and B will be insubstantial alignment around the central portion of the carton and,intermediate the egg receiving cavities 16, so that there are six eggreceiving cavities on opposite sides of the weakened central portion ofthe carton.

When it is desired to divide such a closed carton structure into twosections, slight manual pressure is exerted on opposite ends of thecarton structure and the carton easily breaks neatly and cleanly intotwo individual sections as illustrated in FIG. 2. Also, as shown in FIG.2, the eggs contain within each of the sections of the carton. The fiveslits, positioned substantially in longitudinal alignment when thecarton is in its open position are located (I) at the central edge oflocking flap 18; (2) through the transverse egg separator rib 40; (3)partially through cover back wall member 14 and extending partially intothe concavity which comprises support post 22; (4) through the base ofcover support post 22; (5) and another slit D extending from theopposite edge of the concavity which comprises center post 22 to'theupper portion of front wall 11 of the cover section.

As shown in FIG. 4 these slits are separated by unslit or unweakenedportions of the foam structure, the unweakened portions being inalignment with the slit pattern.

A still further embodiment of the divisible egg carton structure inaccordance with the present invention is shown in FIG. 5 wherein it willbe noted that, in this particular embodiment, there is no cover supportpost 22 in top wall 12 of the carton. As illustrated in FIG. 5 thecentral portion of the carton is characterized by formation of slit Epositioned across the top of transverse rib 40 in the carton bottomcellular section 15. In alignment with slit E is a series ofperforations which extend from the edge of the central portion of flap18 up to and substantially in alignment with slit E, and theperforations to extend beyond slit E through the carton cover memberincluding the carton back wall 14, top wall 12 and front wall 11.

A wide variety of manufacturing techniques may be employed to producethe lines of slits, perforations, and the like, in the egg cartonstructures as described herein. For example, such slits and/orperforations may be incorporated into the carton structure during theprocess of forming a carton utilizing a particularly desired profile inthe central portion of the carton forming mold. Alternatively, suchlines of weakness may be formed in the carton structure during formationof the carton employing, for example, a standard profiled heated wire ora profiled cold knife technique. When it is desired to form such linesof weakness in foamed thermoplastic carton structures however, it hasbeen found desirable to produce such lines of weakness in the cartonscentral area by employing a cold knife, the cutting edge thereof beingsuitably profiled, to effect weakening in the central area of thecarton. Such cutting operations are performed after the carton has beenformed, e.g. utilizing, for example, a matched metal mold thermoformingtechnique to form the carton.

Although the present invention has been described with preferredembodiments, it is to be understood that modifications and variationsmay be resorted to, without departing from the spirit and scope of thisinvention, as those skilled in the art will appreciate. Such variationsand modifications are therefore considered to be within the purview andscope of the appended claims.

What is claimed is:

1. An egg carton structure formed from polystyrene foam comprising acover section and a bottom cellular section hinged to said coversection, said cover section having a concavity in the central portion ofthe top wall of said cover section, said concavity being continuouslyslit along its bottom edge, and said concavity, when said carton isclosed, cooperating with and bearing against a centrally locatedtransverse egg separating member located in said bottom cellularsection, said transverse member being slit along its upper edge and saidcover section being further characterized by having slit means separatedby unweakened areas of said foam, said slit means being in substantiallylongitudinal alignment with said transverse separating member when saidcarton is in an open position whereby when said carton is fractured byapplying manual pressure on opposite ends of said carton saidunweakenecl areas of said foam intermediate said slit means fracturealong a line in longitudinal alignment with said slits.

2. An egg carton structure in accordancewith claim 1 wherein when saidegg carton structure is divided into two sections, opposite sides ofsaid concavity form protective end walls for each of said sections.

3. A polystyrene foam egg carton comprising an inverted dish-like coversection and a bottom cellular section hinged to said cover section, saidcover section comprising front and rear wall sections and opposite endwall sections integrally joined to said front and rear end wall sectionsand a rectangular top wall section in tegrally joined around its edgesto said front, rear, and end wall sections, said top section having acentrally located concavity extending transversely of said coversection, said concavity having a continuous slit along its bottom edge,a series of slit means in substantial alignment with said continuousslit said slit means being separated by unweakened portions of saidfoam; a centrally located transverse egg separating member located insaid bottom cellular section, adapted, when the carton is closed, tocooperate and bear against said concavity, said transverse member havinga continuous slit along its upper edge, said bottom cellular memberbeing further characterized by having a locking flap hinged along onelongitudinal edge thereof, said locking flap having a transverse slit atits outer edge in alignment with the slit in the upper edge of saidtransverse member whereby, when said egg carton structure istransversely divided into two sections by fracturing said carton alongsaid slits, each opposite side of said concavity forms a protective endwall for the cover section of each of said divided sections and oppositesides of said transverse member provide protective end walls for each ofthe cellular sections of said divided sections. l

1. An egg carton structure formed from polystyrene foam comprising acover section and a bottom cellular section hinged to said coversection, said cover section having a concavity in the central portion ofthe top wall of said cover section, said concavity being continuouslyslit along its bottom edge, and said concavity, when said carton isclosed, cooperating with and bearing against a centrally locatedtransverse egg separating member located in said bottom cellularsection, said transverse member being slit along its upper edge and saidcover section being further characterized by having slit means separatedby unweakened areas of said foam, said slit means being in substantiallylongitudinal alignment with said transverse separating member when saidcarton is in an open position whereby when said carton is fractured byapplying manual pressure on opposite ends of said carton said unweakenedareas of said foam intermediate said slit means fracture along a line inlongitudinal alignment with said slits.
 2. An egg carton structure inaccordance with claim 1 wherein when said egg carton structure isdivided into two sections, opposite sides of said concavity formprotective end walls for each of said sections.
 3. A polystyrene foamegg carton comprising an inverted dish-like cover section and a bottomcellular section hinged to said cover section, said cover sectioncomprising front and rear wall sections and opposite end wall sectionsintegrally joined to said front and rear end wall sections and arectangular top wall section integrally joined around its edges to saidfront, rear, and end wall sections, said top section having a centrallylocated concavity extending transversely of said cover section, saidconcavity having a continuous slit along its bottom edge, a series ofslit means in substantial alignment with said continuous slit said slitmeans being separated by unweakened portions of said foam; a centrallylocated transverse egg separating member located in said bottom cellularsection, adapted, when the carton is closed, to cooperate and bearagainst said concavity, said transverse member having a continuous slitalong its upper edge, said bottom cellular member being furthercharacterized by having a locking flap hinged along one longitudinaledge thereof, said locking flap having a transverse slit at its outeredge in alignment with the slit in the upper edge of said transversemember whereby, when said egg carton structure is transversely dividedinto two sections by fracturing said carton along said slits, eachopposite side of said concavity forms a protective end wall for thecover section of each of said divided sections and opposite sides ofsaid transverse member provide protective end walls for each of thecellular sections of said divided sections.